1. Field of Invention
The present invention relates to the field of exercise machines and devices, more specifically an improved method of permitting safe, free-ranging motion in a given exercise.
2. Background Art
All machines we've observed either limit the user to straight up and down motion, or along a fixed arc. In addition, exercise machines generally limit both start-up and finish positions in a given movement. For most machines, the start-up position is also the finish position. This reduces the amount of weight that can be lifted, since in most lifts that start-up position is also the weakest portion of the lift.
Those machines that permit flexibility in start and finish positions (for example, Smith Machine) have a tendency to bind under load, and do not permit natural elliptical motion.
Free-weight lifting eliminates many of these problems, yet lacks the controlled safety and balance of machines.
We believe we've devised a machine that combines the best of both free-weights and machines, permitting a much larger degree of natural motion in a given lift, as well as a variable start-up and finish position, while incoroporating the saftey and control of a machine.
Specifically, our machine permits: 1) simultaneous horizontal and vertical movement of the weight in any given lift (no fixed straight up and down or arc to motion); 2) the ability to lock weight in any position throughout the exercise; 3) the ability to initiate the lift from any position throughout the range of the machine, with ensuing full range of motion; 4) superior ease of movement versus other machines; 5) the use of standard weights (eliminating expense of creating specialized weights); 6) infinite adjustment of gripping apparatus within a given range to suit user arm length; 7) main sliding unit is easily detachable for multitude of additional exercise applications; 8) simple assembly and diassembly (everything comes apart, and the preferred embodiments of this invention employ few or no bolts, etc., in general assembly).
The first four of the features listed above are made possible by our invention's most essential component, which we call the Bearing Sleeve. In its preferred embodiment, the Bearing Sleeve consists of a section of square tubing with ring bearings attached. The bearing sleeve slides over a shaft of square tubing of sufficiently small diameter to fit within it.
These bearing sleeves can accept any number of attachments, including weight-lifting Handlebars, additional receivers, etc. By combining two bearing sleeves, one sliding on a vertical shaft--the other on a horizontal shaft attached to the vertically sliding sleeve--simultaneous horizontal and vertical motion can be achieved.
This two-way motion is crucial to achieve many of the invention's "special effects," including locking and disengaging weight-lifting Handlebars from any position (while retaining full normal range of lift), and the capability of following the body's natural motion rather than a fixed line of motion.
Thus, our machine adjusts to the body, rather than forcing the body to adjust to the machine.
Some brief comparisons of closest known art (listed along with others in attached Information Disclosure Statement):
The VARIABLE WEIGHT EXERCISE MACHINE by Lambert, patent #4010947, employs a bearing-mounted carriage attached to weight stack and weight bearing bars. This device does slide up and down on bearings, but does not permit free, elliptical range of motion; nor does it permit complete control of beginning and end of motion. It is also vastly more complex in operation and parts (for example, it requires specially designed guides, carriage, weight stack, etc., whereas our invention uses generic weight plates and simple square tubing sections).
In BARBELL HAVING AXIALLY MOVING GRIP, #5152731, Troutman shows a pair of sliding cylinders on a barbell. These cylinders employ some form of bearings. The barbell, however, must be specially modified with channels to acommodate the sliding cylinders (no special runners are required for our bearing sleeve). As a free weight device, no methods exist for locking weight-bearing bar during lift, or for maintaining proper balance (a small imbalance during the lift would result in barbell shifting dangerously).
Jack LaLanne shows in WEIGHT LIFTING TYPE EXERCISING DEVICE, #3647209, a cable-based system that claims capacity to lock weights in different positions throughout a lift. His device requires specialized weights, and lacks natural-motion and disengagement capabilities. Most bodybuilders believe that cable systems in general lack the feel and stimulus of lifting weight directly.